A slide fastener is a tool for opening and closing an article used in familiar daily necessities such as clothing items, bags, shoes and miscellaneous goods, as well as industrial goods such as water storage tanks, fishing nets and space suites. The slide fastener is mainly comprised of three parts of a pair of long fastener tapes, a number of elements which are engaging portions of the fastener and are attached along one side edge of each tape, and a slider for controlling opening and closing of the fastener by engaging or separating the elements opposed to each other.
Recently, customer needs for the slide fasteners have diversified, and high added value by means of glazed finishing or various coloring of metallic elements has been developed. For this reason, there have been many situations where gloss polishing or chemical coloring is applied to the metallic elements. In this case, when used for leather goods such as wallets and jackets, discoloration of the elements may occur due to sulfides resulting from the leather. In addition, there is concern that the film on the elements may be scraped with sliding of the slider. Therefore, the surface of the elements is protected with a clear lacquer using a roll coater after the gloss polishing or chemical coloring. For example, Chinese Utility Model No. 203262439 (Patent Document 1) discloses a technique of applying a lacquer to the elements by the roll coating method.
Further, it is known in the art that, in relation to the technique for subjecting the metallic elements to various coloring, a conductive wire is incorporated along the side edge portion where a row of elements of the fastener tape is arranged, and electrodeposition coating is then performed. An example of prior patents disclosing this type of technique includes Japanese Patent Application Public Disclosure (KOKAI) No. H05-123209 A1 (Patent Document 2).